阅读说明：本技术 在igbt芯片上集成温度传感器的方法 (Method for integrating temperature sensor on IGBT chip ) 是由 潘嘉 杨继业 邢军军 黄璇 张须坤 陈冲 于 2019-09-25 设计创作，主要内容包括：本申请公开了一种在IGBT芯片上集成温度传感器的方法,属于半导体制造技术领域。该方法包括在硅衬底上生成栅氧化层；在栅氧化层上生成多晶硅栅层；在多晶硅栅层上生成氧化层；在氧化层上生成温度传感器poly层；在温度传感器poly层中形成P型区；刻蚀预设区域的温度传感器poly层,直到露出氧化层；在P型区中形成N型区；刻蚀去除N型区和P型区表面的温度传感器poly层、未被温度传感器poly层覆盖的氧化层、预定区域的多晶硅栅层；同时制作温度传感器接触孔和IGBT接触孔；解决了目前IGBT芯片的结温监测方案复杂、精确度不高的问题；达到了实时精确监测IGBT芯片的结温,快速进行温度响应的效果。(The application discloses a method for integrating a temperature sensor on an IGBT chip, and belongs to the technical field of semiconductor manufacturing. The method comprises generating a gate oxide layer on a silicon substrate; generating a polysilicon gate layer on the gate oxide layer; generating an oxide layer on the polysilicon gate layer; generating a temperature sensor poly layer on the oxide layer; forming a P-type region in a temperature sensor poly layer; etching the temperature sensor poly layer in the preset area until the oxide layer is exposed; forming an N-type region in the P-type region; etching and removing the temperature sensor poly layer, the oxide layer which is not covered by the temperature sensor poly layer and the polysilicon gate layer in the preset area on the surfaces of the N-type area and the P-type area; simultaneously manufacturing a temperature sensor contact hole and an IGBT contact hole; the problems that the junction temperature monitoring scheme of the existing IGBT chip is complex and low in accuracy are solved; the effects of accurately monitoring the junction temperature of the IGBT chip in real time and quickly carrying out temperature response are achieved.)

1. A method of integrating a temperature sensor on an IGBT chip, the method comprising:

generating a gate oxide layer on a silicon substrate;

generating a polysilicon gate layer on the gate oxide layer;

generating an oxide layer on the polysilicon gate layer;

generating a temperature sensor poly layer on the oxide layer;

injecting boron ions into the preset depth in the temperature sensor poly layer to form a P-type region;

etching the temperature sensor poly layer in the preset area until the oxide layer is exposed;

forming an N-type region in the P-type region;

etching and removing the temperature sensor poly layer on the surfaces of the N-type region and the P-type region, the oxide layer which is not covered by the temperature sensor poly layer and the polysilicon gate layer in a preset region;

and simultaneously manufacturing a temperature sensor contact hole and an IGBT contact hole, wherein the temperature sensor contact hole comprises a first contact hole and a second contact hole, the first contact hole penetrates through the N-type region, the second contact hole penetrates through the P-type region, and the IGBT contact hole penetrates through the gate oxide layer and is communicated with the silicon substrate.

2. The method of claim 1, wherein simultaneously fabricating a temperature sensor contact hole and an IGBT contact hole comprises:

depositing an insulating medium layer;

and simultaneously manufacturing the temperature sensor contact hole and the IGBT contact hole.

3. The method of claim 1, wherein said implanting boron ions to a predetermined depth in said temperature sensor poly layer to form a P-type region comprises:

implanting boron ions into the preset depth in the temperature sensor poly layer, and annealing to form the P-type region;

wherein the implantation dosage of the boron ions is 5E 13-5E 15 ions/m³。

4. The method of claim 1, wherein forming an N-type region in the P-type region comprises:

and implanting arsenic ions or phosphorus ions into a preset region in the P-type region, and annealing to form the N-type region.

5. The method of claim 4, wherein the ions are implanted at a dose of 5E 14-5E 15 ions/m³The diffusion temperature is 900-1100 ℃.

6. The method of claim 1, wherein the polysilicon gate layer has a thickness of 5000A to 15000A.

7. The method of claim 1, wherein the oxide layer has a thickness of 300A to 1500A.

8. The method of claim 1, wherein the thickness of the temperature sensor poly layer is 1500A-15000A.

Technical Field

The application relates to the technical field of semiconductor manufacturing, in particular to a method for integrating a temperature sensor on an IGBT chip.

Background

An IGBT (Insulated Gate Bipolar Transistor) is a power Semiconductor device composed of BJT (Bipolar Junction Transistor) and MOS (Metal-Oxide-Semiconductor Field-Effect Transistor), and has the characteristics of reduced on-state voltage, fast response speed, and simple control. The IGBT device is used as a core device in new energy power electronic products, is widely popularized in recent years, and application products are evolved from traditional products such as white home appliances, industrial frequency conversion and welding machines to high-end products such as new energy automobiles.

The IGBT chip in the new energy automobile needs to monitor the temperature more accurately in real time, and a system scheme of integrating a temperature sensor in a module is generally adopted at present. However, integrating a temperature sensor within the system module increases the cost of the entire module, and the system becomes complex, reducing reliability.

Disclosure of Invention

The application provides a method for integrating a temperature sensor on an IGBT chip, which can solve the problems of complex junction temperature monitoring scheme and low accuracy of the IGBT chip in the related technology.

In one aspect, an embodiment of the present application provides a method for integrating a temperature sensor on an IGBT chip, where the method includes:

generating a gate oxide layer on a silicon substrate;

generating a polysilicon gate layer on the gate oxide layer;

forming an oxide layer on the polysilicon gate layer

Generating a temperature sensor poly layer on the oxide layer;

injecting boron ions into a preset depth in the temperature sensor poly layer to form a P-type region;

etching the temperature sensor poly layer in the preset area until the oxide layer is exposed;

forming an N-type region in the P-type region;

etching and removing the temperature sensor poly layer, the oxide layer which is not covered by the temperature sensor poly layer and the polysilicon gate layer in the preset area on the surfaces of the N-type area and the P-type area;

and simultaneously manufacturing a temperature sensor contact hole and an IGBT contact hole, wherein the temperature sensor contact hole comprises a first contact hole and a second contact hole, the first contact hole penetrates through the N-type region, the second contact hole penetrates through the P-type region, and the IGBT contact hole penetrates through the gate oxide layer and is communicated with the silicon substrate.

Optionally, simultaneously, make temperature sensor contact hole and IGBT contact hole, include:

depositing an insulating medium layer;

and simultaneously manufacturing a temperature sensor contact hole and an IGBT contact hole.

Optionally, implanting boron ions into the predetermined depth in the temperature sensor poly layer to form a P-type region, including:

injecting boron ions into the preset depth in the temperature sensor poly layer, and annealing to form a P-type region;

wherein the implantation dosage of the boron ions is 5E 13-5E 15 ions/m³。

Optionally, forming an N-type region in the P-type region includes:

and implanting arsenic ions or phosphorus ions into a predetermined region in the P-type region, and annealing to form an N-type region.

Optionally, forming an N-type region in a predetermined region of the P-type region by ion implantation, including:

and implanting arsenic ions into a predetermined region in the p-type region and annealing to form an N-type region.

Optionally, the implantation dose of the ions is 5E 14-5E 15 ions/m³The diffusion temperature is 900-1100 ℃.

Optionally, the thickness of the polysilicon gate layer is 5000A to 15000A.

Optionally, the thickness of the oxide layer is 300A-1500A.

Optionally, the thickness of the temperature sensor poly layer is 1500A-15000A.

The technical scheme at least comprises the following advantages:

generating a gate oxide layer on a silicon substrate, generating a polysilicon gate layer on the gate oxide layer, generating an oxide layer on the polysilicon gate layer, generating a temperature sensor poly layer on the oxide layer, generating a P-type area and an N-type area in the temperature sensor poly layer, etching and removing the temperature sensor poly layer on the surfaces of the N-type area and the P-type area, and simultaneously manufacturing a temperature sensor contact hole and an IGBT contact hole; under the condition of not influencing the electrical characteristics of the original IGBT, the temperature sensor is integrated on the IGBT chip in the production process of the IGBT chip, so that the problems of complex junction temperature monitoring scheme and low accuracy of the current IGBT chip are solved; the junction temperature of the IGBT chip is accurately monitored in real time, the temperature response is rapidly carried out, and the short circuit and overheating protection of the IGBT chip is more accurate, safe and reliable.

Drawings

In order to more clearly illustrate the detailed description of the present application or the technical solutions in the prior art, the drawings needed to be used in the detailed description of the present application or the prior art description will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a flowchart of a method for integrating a temperature sensor on an IGBT chip according to an embodiment of the present application;

FIG. 2 is a partial schematic view of a product structure in the manufacturing process of an IGBT chip in the embodiment of the application;

FIG. 3 is a partial schematic view of a product structure in the manufacturing process of an IGBT chip in the embodiment of the application;

FIG. 4 is a partial schematic view of a product structure in the manufacturing process of an IGBT chip in the embodiment of the application;

FIG. 5 is a partial schematic view of a product structure in the manufacturing process of an IGBT chip in the embodiment of the application;

FIG. 6 is a partial schematic view of a product structure in the manufacturing process of an IGBT chip in the embodiment of the application;

FIG. 7 is a partial schematic view of a product structure in the manufacturing process of an IGBT chip in the embodiment of the application;

FIG. 8 is a partial schematic view of a product structure in the manufacturing process of an IGBT chip in the embodiment of the application;

FIG. 9 is a partial schematic view of a product structure in the manufacturing process of an IGBT chip in the embodiment of the application;

FIG. 10 is a partial schematic view of a product structure in the manufacturing process of an IGBT chip in the embodiment of the application;

wherein 21 denotes a silicon substrate; 22 denotes a gate oxide layer; 23 denotes a polysilicon gate layer; 24 denotes an oxide layer; 25 denotes a temperature sensor poly layer; 251 denotes a P-type region; 252 represents an N-type region; 31 denotes a first contact hole; 32 denotes a second contact hole; and 41 denotes an IGBT contact hole.

Detailed Description

The technical solutions in the present application will be described clearly and completely with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; the connection can be mechanical connection or electrical connection; the two elements may be directly connected or indirectly connected through an intermediate medium, or may be communicated with each other inside the two elements, or may be wirelessly connected or wired connected. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

In addition, the technical features mentioned in the different embodiments of the present application described below may be combined with each other as long as they do not conflict with each other.

With the continuous improvement of the performance of the IGBT, the power density of the IGBT in application is higher and higher, and the faced working condition is more and more complex. In the fields of automotive electronics, new energy automobiles and the like, the performance requirement on the IGBT is higher, and when the temperature of an IGBT chip is too high, the chip faces failure risks. At present, the over-temperature protection of the IGBT can be realized by detecting the junction temperature of an IGBT chip. Because the IGBT is packaged inside the tube shell, the junction temperature cannot be directly measured, the currently adopted mode comprises the steps of packaging the NTC thermistor when the IGBT module is packaged, and then reflecting the junction temperature of the IGBT by using the resistance value of the NTC thermistor detected by an external circuit, however, the placement position of the NTC thermistor and the external circuit not only influence the accuracy of a detection result, but also increase the cost of the whole module, and the system becomes complicated.

In order to detect the junction temperature of the IGBT more accurately and in real time, the embodiment of the present application provides a method for integrating a temperature sensor on an IGBT chip, that is, in the manufacturing process of the IGBT chip, the temperature sensor is integrated on the IGBT chip. As shown in fig. 1, a method for integrating a temperature sensor on an IGBT chip provided in an embodiment of the present application may include the following steps:

step 101, growing a gate oxide layer on a silicon substrate.

A gate oxide layer is thermally grown on a silicon substrate, as shown in fig. 2, with a gate oxide layer 22 grown on a silicon substrate 21.

Step 102, a polysilicon gate layer is generated on the gate oxide layer.

A polysilicon gate layer is deposited on the gate oxide layer, and as shown in fig. 3, a polysilicon gate layer 23 is formed on the gate oxide layer 22. Optionally, the polysilicon gate layer is generated by a chemical vapor deposition process. Optionally, the thickness of the polysilicon gate layer 23 is 5000A to 15000A.

And 103, generating an oxide layer on the polysilicon gate layer.

As shown in fig. 4, an oxide layer 24 is provided on the polysilicon gate layer 23. Optionally, the thickness of the oxide layer is 300A-1500A.

The oxide layer is used for isolating an IGBT device manufactured on the silicon substrate and a temperature sensor integrated on the same silicon substrate.

Step 104, a temperature sensor poly layer is formed on the oxide layer.

As shown in fig. 5, the surface of the oxide layer 24 has a temperature sensor poly (polysilicon) layer 25.

Optionally, the thickness of the temperature sensor poly layer is 1500A-15000A.

In step 105, boron ions are implanted into the predetermined depth in the temperature sensor poly layer to form a P-type region.

The position and the ion implantation dosage of a P-type area in the temperature sensor poly layer are predetermined, and boron ions are implanted into a predetermined depth in the temperature sensor poly layer by using an ion implanter. Because the ion implantation can damage the crystal lattice of the silicon wafer, the silicon wafer is annealed after the boron ion implantation is finished. As shown in fig. 6, a P-type region 251 is formed in the temperature sensor poly layer 25.

Optionally, the implantation dosage of the boron ions is 5E 13-5E 15 ions/m³。

Before ion implantation, the surface of the silicon wafer needs to be cleaned and dried. Before ion implantation, the regions of the silicon wafer which do not need ion implantation are covered by photoetching, etching and other processes, and the regions which need ion implantation are exposed.

And 106, etching the temperature sensor poly layer in the preset area until the oxide layer is exposed.

And (3) spin-coating a photoresist on the surface of the silicon wafer, transferring the mask pattern into the photoresist through ultraviolet exposure, and developing the surface of the silicon wafer by using a developing solution to obtain the photoresist corresponding to the mask pattern. The mask is designed in advance according to the product structure, and the preset area to be etched is determined according to the mask.

And etching away the temperature sensor poly layer without the photoresist covering part until the oxide layer is exposed.

As shown in fig. 7, a portion of the temperature sensor poly layer 25 is etched away.

In step 107, an N-type region is formed in the P-type region.

Exposing the surface of a temperature sensor poly layer needing to form an N-type region through a photoetching process, and covering the part outside the N-type region with photoresist; arsenic ions or phosphorus ions are implanted into a predetermined region within the P-type region in the temperature sensor poly layer 25, and annealing is performed after the ions are implanted into the predetermined region within the P-type region to form an N-type region. The predetermined region into which the arsenic ions or the phosphorus ions are implanted is determined in advance according to the product structure.

Optionally, the implantation dosage of the arsenic ions or the phosphorus ions is 5E 14-5E 15 ions/m³。

As shown in fig. 8, a P-type region 251 and an N-type region 252 are formed in the temperature sensor poly layer 25.

The P-type region 251 and the N-type region 251 are in contact in the temperature sensor poly layer to form a PN junction. The conductivity of the PN junction changes along with the rise of the temperature, and the external detection circuit can determine the temperature change inside the IGBT device by detecting the conductivity of the PN junction, so that the effect of accurately monitoring the temperature of the IGBT in real time is achieved.

And 108, etching and removing the temperature sensor poly layer on the surfaces of the N-type region and the P-type region, the oxide layer which is not covered by the temperature sensor poly layer and the polysilicon gate layer in the preset region.

And etching and removing the temperature sensor poly layer, the oxide layer which is not covered by the temperature sensor poly layer and the polysilicon gate layer in the preset area on the surfaces of the N-type area and the P-type area in sequence. During the etching of each portion, portions that are not required to be etched are protected by a photolithography process. The portions to be removed by etching are predetermined by the pattern on the reticle.

As shown in fig. 9, after etching, the surfaces of the P-type region 251 and the N-type region 252 are not provided with the temperature sensor poly layer, the oxide layer 24 is covered by the temperature sensor poly layer, and the polysilicon layer 23 is etched to remove a portion to expose the gate oxide layer 22 under the polysilicon gate layer 23. The polysilicon gate layer 23 is not completely covered by the oxide layer 24.

And step 109, simultaneously manufacturing a temperature sensor contact hole and an IGBT contact hole.

The temperature sensor contact hole comprises a first contact hole and a second contact hole, the first contact hole penetrates through the N-type region, and the second contact hole penetrates through the P-type region. The IGBT contact hole penetrates through the gate oxide layer and is communicated with the silicon substrate.

Optionally, an insulating medium layer is deposited, and a temperature sensor contact hole and an IGBT contact hole are simultaneously manufactured. Specifically, after an insulating medium layer is deposited, photoresist is coated in a spinning mode, areas which do not need to be etched are protected through the photoresist, areas corresponding to a temperature sensor contact hole and an IGBT contact hole are etched in the insulating medium layer, then an N-type area and a P-type area in a temperature sensor poly layer are etched, and a first contact hole penetrating through the N-type area and a second contact hole penetrating through the P-type area are obtained; and etching an IGBT contact hole at the same time; the positions and patterns of the temperature sensor contact hole and the IGBT contact hole are determined by a mask. And after etching the contact hole of the temperature sensor and the contact hole of the IGBT, depositing metal.

As shown in fig. 10, a second contact hole 32 is formed in the P-type region 251, the second contact hole 32 is communicated with the P-type region 251, a first contact hole 31 is formed in the N-type region 252, and the first contact hole 31 is communicated with the N-type region 252; the IGBT contact hole 41 penetrates the gate oxide layer 22 and communicates with the silicon substrate 21.

The process steps for manufacturing the IGBT contact hole and the temperature sensor contact hole are the prior art and are not repeated herein.

In the embodiment of the present application, an IGBT device is further fabricated on the silicon substrate, that is, the silicon substrate includes a collector region, a buffer region, an emitter region, a source region, and the like of the IGBT, and a device unit structure of the IGBT is not shown in the figure. Since the manufacturing process of the IGBT is the prior art, details of the IGBT manufacturing process are not described in the embodiments of the present application.

The temperature sensor and the IGBT device may be processed and molded at the same time, or the temperature sensor and the IGBT device may be processed separately, which is not limited in this application.

Compared with the existing IGBT device, the chip structure is additionally provided with a gate oxide layer, a polycrystalline silicon gate layer, an oxide layer, a temperature sensor poly layer, a P-type region and an N-type region in the temperature sensor poly layer, a first contact hole penetrating through the N-type region and a second contact hole penetrating through the P-type region.

In summary, in the method for integrating the temperature sensor on the IGBT chip provided in the embodiment of the present application, the gate oxide layer is formed on the silicon substrate, the polysilicon gate layer is formed on the gate oxide layer, the oxide layer is formed on the polysilicon gate layer, the temperature sensor poly layer is formed on the oxide layer, the P-type region and the N-type region are formed in the temperature sensor poly layer, and after the temperature sensor poly layers on the surfaces of the N-type region and the P-type region are etched and removed, the temperature sensor contact hole and the IGBT contact hole are simultaneously manufactured; under the condition of not influencing the electrical characteristics of the original IGBT, the temperature sensor is integrated on the IGBT chip in the production process of the IGBT chip, so that the problems of complex junction temperature monitoring scheme and low accuracy of the current IGBT chip are solved; the junction temperature of the IGBT chip is accurately monitored in real time, the temperature response is rapidly carried out, and the short circuit and overheating protection of the IGBT chip is more accurate, safe and reliable.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications of this invention are intended to be covered by the scope of the invention as expressed herein.